Skenazy argues that fear and worry have essentially hijacked childhood. American parents, influenced by a steady diet of outrageous and extreme crime stories on TV and in movies, have become notorious hoverers who won't let their kids out of sight.

But those crimes, she says, are rare. In fact, crime stats show that the United States today is safer than it was in the 1970s and 80s, when today's parents were kids.

"The way we have come to think of safety in 2009 is really different from the old definition of safety, which was a pretty sane one," Skenazy said. Parents used to be guided by what they considered reasonably safe.

"Certainly letting your kids go two doors down at age 8 is really safe unless they are crossing train tracks," she said. "Two doors down is really something we wouldn't have thought twice of as kids and there is a reason: because that is what a neighborhood is."

"Our new definition of safety," she said, "is something has to be 99.999 percent safe before we can let our kids participate."

This fear of letting kids out of our sight may do more harm than good, she said. Giving kids the chance to play basketball with their buddies a couple houses away, or letting them walk to school on their own boosts their confidence and sends a powerful message that you trust them.

"If parents want to raise the kinds of kids they are trying to raise - safe, happy, well-adjusted kids who know how to organize a game of four-square - you've got to let them outside and you have to take some steps back," she said.

Which is not to say you shouldn't keep tabs on your kids, she said.

Skenazy, who says she hates danger and is a worrier by nature, acknowledges it's hard to let your child go off alone, even if it's just a couple doors down the street. She worried when she let her son take the subway but he wanted to try it.

Her advice: start small and think about what your own parents let you do when you were a kid. Use that as a guide for making decisions about what to let your child do on her own.

She said before she decided to let her son walk to the nearby lake with his friends she thought about the bear that's been sighted in the local woods. She reminded herself that while having a bear roaming around is scary, the animal has never attacked anyone.

In the end, she told her son to go.

"I think three kids going to the lake and fishing is what I want my kid to be doing this summer. Not playing and staying inside and playing a Wii fishing game."

What about you? Do you let your kids play without supervision? How about walk to school without an adult?